Thanks Friends...
My car has done 7000 Kms so i think i should wait for 10000km and then go for CNG....
I have also check with two Toyota dealers ( TOYOTA GT and TOYOTA RAWAL) there comments about CNG was not very impressive as they told me that they have registered cases of Head and values faults in new corolla just 30k to 40k driven on CNG, but they were saying if you drive ur car atleast 4 to 5 KM daily on petrol then you can delay this work to 100000 km plus millage.
I have check on landirenzo website, they have different emulators and advancers for different type of Engines, but i doubt in Pakistan they were using the same for every engine.
Toyota GT gave me hope that if i will install CNG kit from them then they will take full responsibility that my car work fine on CNG, but Engine warranty and rear shocks warranty will be void...